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Is it possible to make a specialized spark gap device that operates similarly to a transitor? Answered

I have a serious issue with utilizing an H-bridge to switch polarity of high voltage electromagnets. The voltage is roughly 110 DC rectified from mains. Every mosfet I use has exploded when I tried to switch the mosfets. I tried using relays but they keep arcing and tripping my breaker. I would very much like to know if it was possible to make a spark gap that works similar to a NPN transistor.

I believe that the nature of my problem is being a little skewed. You seem to be under the assumption that I am having trouble with the kickback. What I really have a problem with is that during the switching of relay 1 and 4 to 2 and 3 the resistances of the airgaps between the contacts is less than 60 ohms thus allowing the electricity to short circuit from relay 1 to relay 3. The real question I wanted input on is that if a spark gap were to be made at 1.25 the distance the arc can occur, and a plate were placed halfway between the anode and cathode would applying a charge to the plate allow the arc to jump between the 2 terminals through the plate?

They are already rectified and so therefore can not send a reverse voltage through the positive leads. There is also a diverter that I use to divert the kickback to ground but it only works if the relays can reach a resistance of >60 ohms before an arc is started. I also tested the circuit without the electromagnets and still get the same result so if you want to still claim it's a problem with the coils go ahead, but if my problem were that simple I would have gotten the answer from wiki.

the Vg max was somewhere close to 200v but I never used the mosfets with this exact circuit. I ran a switching test to double check the bias, when the mosfet exploded I chose to use relays instead. I know exactly where my problem is and the question I posted was whether a pseudo-vacuum tube / spark gap transistor were possible. I don't like the idea of using MOSFETs primarily because there will be absolutely zero heat dissapation capacity along with the circuit operating in a high ambient heat environment.

If you know your exact problem, you don't need an answer. I am telling you that the diodes, as drawn, are connected wrongly, and won't work. You are only switching an electromagnet, and not igniting a nuclear weapon.

What would you suggest I do to correct the arcing of my relays? You are incorrect about the diodes being wrong simply because the electromagnets work until the relays are triggered then relays flash a bright green and my breaker trips. As to using spark gap transistor idea I do need the precision and modular scalability. Providing that data is favorable the system will need to be scaled to function in the Kv range with megahertz switching speeds.

Its also occurred to me that you are assuming that one set of contacts is fully released before the others close - that's not true with relays, unless you are VERY careful to design delays in. So you are crow-barring your supply that way, as well as adding sustaining arcs, because the diodes are wrong.

I have already designed a circuit to divert back current to ground but the problem resides in the fact that the arcing in my relays is creating a path that has less resistance than the rest of the circuit so it bypasses my circuit.

I would have already opted to use these if it was only within my price range. 4 of these would set me back at least $200 which is not very cost efficient considering that this is for a simple proof of concept project and not a fully funded production model.